Boris Johnson would be voters' choice to replace David Cameron as Conservative leader if he stood down before the next election, according to a poll released today.

The London Mayor was the preferred candidate of 24% of those questioned by YouGov for the Sunday Times, followed by Foreign Secretary William Hague on 14%, ex-leadership candidate David Davis on 6%, Chancellor George Osborne on 3% and Education Secretary Michael Gove on 2%.

Mr Johnson was an even more popular choice as next leader among Conservative voters, with 33% naming him as the best replacement for Mr Cameron, against 24% for Mr Hague and 7% for Mr Davis. And several major Tory donors told the paper that they regard Mr Johnson as a potential future leader.

The poll reflected the so-called “Boris bounce” which the mayor has enjoyed during the London Olympics, garnering favourable headlines even when left dangling from a zipwire in a stunt which went wrong. The proportion of people saying he would make a better leader than Mr Cameron has risen from 23% in July to 30% now.

It confirmed that the Conservatives are still trailing Labour in public opinion, with Ed Miliband's party backed by 44% - 12 points clear of the Tories under Mr Cameron on 32%. Liberal Democrats were on 10%.

Some 58% said Mr Cameron was doing badly as Prime Minister, against 37% who said he was doing a good job. While 39% said he should stay in the job, 37% - including 14% of Conservative supporters - said that he should stand down and let someone else lead the party.

And just 25% approved of the Government's record so far, compared to 62% who did not. Some 64% said that the Conservatives and Liberal Democrats were working together badly in coalition, while just 30% said they were working well.

However, the survey also raised doubts over whether Mr Johnson could revive the Tories' electoral fortunes, with 19% saying he would make them more likely to vote Conservative but 17% less likely, and 55% of voters saying it would make no difference at all.

With figures released last week showing the party's income was cut by nearly half last year, dropping by almost £20 million to its lowest level since 2003, the views of wealthy donors who have supported the Tories in the past will carry some weight in determining the prospects of potential future leaders.

Financier Peter Hall, who has given more than £450,000 to the Conservatives, told the Sunday Times that Mr Johnson could be the right leader for Britain if the country sinks into a very deep recession.

“Boris's great strength is his confidence and his optimism and his ability to, in an almost Churchillian way, inspire people to hope for a better future,” said Mr Hall.

Entrepreneur Hugh Osmond, who gave the Tories almost £100,000 in 2008 and 2009 but has not made a donation since the general election, said: “I've always thought that Boris espoused principles and ideals more in line with the things that I believe in than David Cameron.”

And Conservative treasurer Lord Fink said: “I don't think there is a job vacancy, but if there was and if Boris wanted to run, he would be an extremely strong candidate. That is not to say there are not some other extremely good candidates.”

:: YouGov questioned 1,787 people on August 2 and 3 for the Sunday Times.

One Conservative MP today suggested that Mr Johnson could replace Mr Cameron as Conservative leader by the time of the general election scheduled for 2015.

Nadine Dorries - a regular critic of the current Tory leadership -
said that a growing number of Conservative MPs regard Mr Johnson as someone who could win the election for them, and even claimed that some within Mr Cameron's "inner circle" privately agree.

Writing in the Mail on Sunday, the Mid-Bedfordshire MP said: "On our present trajectory, the Conservatives are facing electoral oblivion under Mr Cameron.

"We are going to have our backsides metaphorically kicked in next
year's county council elections, we will suffer big losses to UKIP in the 2014 Euro elections and the year after that we face the prospect of defeat in the general election.

"In my view, it is by no means impossible that Boris will have replaced Mr Cameron by then."

Ms Dorries said the London Mayor has "a proven track record as a winner" and "an appeal and charisma that David Cameron lacks". "He has a
searing intellect, is a classical scholar, accomplished author and journalist and makes Cameron and Osborne look pale by comparison," she said.

And she insisted that earlier controversy over his private life will not block his path to the leadership: "MPs facing the loss of their
seat in 2015 will be quite happy to forgive his indiscretions if they think, as a growing number do, that he is a winner...

"He embodies those rare qualities that Cameron and Osborne can only dream of - he wins elections and the voters love him."

Mr Hague told Sky News: "Boris is doing a great job as Mayor of London and people love him the more they see him, and that's great. I am
one of his biggest fans and campaigned hard for his re-election.

"But I think it is true to say - and certainly it is true for me -
that I hope and believe that we are not looking for a long time for any
new leader of the Conservative Party.

"We have got the best leader and the best Prime Minister we have had in a long time, and I think it will be some time before we Conservatives are looking for a new leader."